Correlation between physical activity and anthropometric measurements among children and adolescents.

Objectives: The purpose of this study was to measure the association between the level of physical activity and sedentary conditions with anthropometric measurements of children and adolescents.

Methods: This cross-sectional descriptive study consisted of a convenience sample of 400 children and adolescents from public schools in Itapevi-SP, Brazil. The Physical Activity Checklist Interview or LAF "Lista de Atividades Físicas" in a Brazilian version, was administered in a face-to-face interview on a school day and allowed assessment of sedentary behavior and physical activity on the previous day. Anthropometric measurements included body weight, sex, age, and lower limb posture. The participants were photographed in the frontal and sagittal planes, and the photos were analyzed using postural assessment software (PAS/SAPO). Pearson's tests were applied to analyze correlations.

Results: Children and adolescents show a greater tendency toward valgus knees with increasing body mass (r = ‒0.33). On average, girls have a larger Q angle. Ankles are less likely to become valgus with increasing age and mass (r = ‒0.18 and ‒0.23, respectively). The horizontal alignment of the pelvis is mostly in anteversion with a significant increase with age (r = 0.27) and a slight increase with mass (r = 0.15). The knee and ankle tend to be less hyperextended and more dorsiflexed from the age of 10, with no correlation with the other variables. It was not possible to observe a clear relationship between the time spent in physical activity and sedentary behavior and the postural angles mentioned above.

Conclusion: Although correlations were found between age, sex and body mass, and postural angles, notably pelvis alignment, Q angle, knee, ankle, sex, and body weight, there was no correlation between the time spent in physical activity, sedentary behavior, and lower limb posture.